Chronic cough

Introduction to chronic cough The definition of chronic cough is currently considered to be coughing for more than 3 weeks, and the cough without evidence of obvious lung disease is called chronic cough. Cough is often the only symptom of the patient. Cough is one of the common clinical symptoms of the respiratory system. Chronic cough is the most common cough variant asthma. The disease is cough as the only symptom, so the clinical features are lack of specificity, and the rate of misdiagnosis is very high. Therefore, for a chronic recurrent cough should be thought of the possibility of the disease. Since about 50%-80% of children with cough variant asthma develop into typical asthma, about 10-33% of adults with cough variant asthma can develop into typical asthma. Many authors consider cough variant asthma as a precursor to asthma, so early diagnosis and early treatment of cough variant asthma is important to prevent asthma. basic knowledge The proportion of sickness: 0.14% - 0.23% Susceptible people: no special people Mode of infection: non-infectious Complications: Asthma Respiratory infections

Chronic cough cause

Pleural disease (20%):

Such as various reasons for pleurisy, pleural mesothelioma, spontaneous pneumothorax. Cardiovascular disease: mitral stenosis or other causes of left heart failure caused by pulmonary congestion or pulmonary edema. Central nervous factors: The impulse from the cerebral cortex is transmitted to the medullary cough center, such as encephalitis and meningitis.

Cough variant asthma (28%):

Cough persists for more than 4 weeks, often at night or in the morning, exercise, cold cough after a cold, no infection, antibiotic treatment is invalid. Bronchodilator treatment significantly relieved cough. Pulmonary ventilation is normal, and bronchial provocation tests suggest high airway reactivity. A family history of allergies or allergies. Except for other causes of coughing.

Respiratory diseases (25%):

When the entire respiratory tract mucosa of the nasopharynx to the small bronchus is stimulated, it can cause cough, such as pharyngitis, trachea-bronchitis, bronchiectasis, bronchial asthma, allergic substances, lung bacterial infections, etc.

Upper airway cough syndrome (14%):

Various kinds of rhinitis, sinusitis, pharyngitis, adenoid hypertrophy and other upper airway diseases caused by cough.

Gastroesophageal reflux cough (3%):

Cough is mostly at night; cough is mostly after eating, accompanied by upper abdominal discomfort.

Eosinophilic bronchitis (10%):

Chronic cough, high percentage of eosinophils in sputum, effective hormone therapy.

Chronic cough prevention

1, do not eat spicy spicy food, avoid tobacco and alcohol, eat more fruits and vegetables.

2, keep your mood comfortable, don't worry if you are in trouble.

3. Actively exercise and enhance your own resistance.

4, actively treat the primary disease, so as not to aggravate the condition.

Chronic cough complications Complications asthma respiratory infection

Many diseases are associated with cough symptoms, and diseases that need to be differentiated from cough variant asthma include COPD, chronic bronchitis, cough caused by gastroesophageal reflux, recurrent respiratory tract infections (RRTI), typical asthma, and postnasal drip synthesis. Disease (PNDS), endobronchial tuberculosis, and angiotensin-converting enzyme inhibitor-induced cough, which are common causes of chronic cough, and need to be carefully excluded in the diagnosis of cough variant asthma. In addition, chronic heart failure, esophageal hiatal hernia, hypertension, airway inflammation, tumors, foreign bodies, and smoke stimuli, anxiety, etc. can lead to chronic cough.

Chronic cough symptoms Common symptoms Sore throat, wheezing, dry cough, metal tone, cough, water, cough, bronchospasm

Chronic cough is the most common cough variant asthma. The disease is cough as the only symptom, so the clinical features are lack of specificity, and the rate of misdiagnosis is very high. Therefore, for a chronic recurrent cough should be thought of the possibility of the disease. Since about 50%-80% of children with cough variant asthma develop into typical asthma, about 10-33% of adults with cough variant asthma can develop into typical asthma. Many authors consider cough variant asthma as a precursor to asthma, so early diagnosis and early treatment of cough variant asthma is important to prevent asthma. Mainly have the following clinical features:

1, the incidence of people: the incidence of children is high, it has been found that more than 30% of children with dry cough and cough variant asthma. In adults, the age of onset of cough variant asthma is higher than that of typical asthma. About 13% of patients are older than 50 years old, and middle-aged women are more common.

2, clinical manifestations: cough may be the only symptom of asthma, mainly long-term intractable dry cough, often induced by inhalation of irritating odor, cold air, exposure to allergens, exercise or upper respiratory tract infection, some patients have no incentives. More intensified at night or in the early hours of the morning. Some patients have a certain seasonality, with more spring and autumn. Most patients have been treated with cough and expectorant drugs and antibiotics for a period of time, almost no effect, and the use of glucocorticoids, anti-allergic drugs, 2 receptor agonists and theophylline can be alleviated.

3, history of allergies: patients themselves may have a clear history of allergic diseases, such as allergic rhinitis, eczema and so on. Some patients can be traced back to a family history of allergies.

4, signs: Although it can also have bronchospasm, but most occur in the peripheral bronchioles or transient paralysis, so the body can not hear or rarely hear wheezing sound.

Chronic cough examination

1, airway reactivity increased, mostly light-moderate increase. The test procedure can induce irritating coughs at similar onset.

2, lung function damage between normal people and typical asthma.

3, skin allergen test can be positive.

4. Serum IgE levels increase.

5, some patients may be positive for bronchiectasis test, when there is a positive reaction, it indicates that there is a certain state of paralysis and obstruction in the airway.

6, peripheral blood eosinophil count increased, serum ECP levels increased.

Diagnosis of chronic cough

The following can be used as a reference for the diagnosis of cough variant asthma:

1, cough recurrent episodes lasting more than 1 month, mainly dry cough; often at night and / or early morning attack or exercise after aggravation.

2, cough is mostly related to contact with irritating odor, cold air, contact with allergen or excessive exercise.

3, may have allergic rhinitis or other allergic disease history or family history, allergen test positive or increased IgE levels.

4. Increased airway reactivity.

5, antibiotics or symptomatic treatment is invalid for more than 2 weeks, and is effective against allergy treatment or bronchodilator.

6. Exclude chronic cough caused by other chronic respiratory diseases.

Auxiliary diagnostic measures

In the case of patients who only complain of long-term cough (time greater than two weeks), the possibility of cough variant asthma should be considered. Based on detailed medical history, careful physical examination, and summary of clinical features, the following methods can be used to confirm the diagnosis:

1. If the FEV1 or PEFR measured at the time of the patient's visit is less than 70% of the normal value, the bronchodilator can be inhaled, such as 2% salbutamol 200g. After 15 minutes, the above indicators are retested, such as the improvement rate of FEV1 and PEFR 15%, can diagnose the disease.

2. If the patient is expected to have a normal FEV1 and PEFR 70% at the time of the visit, the bronchial provocation test may be performed cautiously.

3. Determination of PEFR day and night changes within 24 hours for three consecutive days is a simple and effective screening method for diagnosing such bronchial asthma. If the PEFR mutation rate is 20%, the disease can be diagnosed.

Although the measurement of lung function indicators is an effective means of early detection of such asthma, it has been found that the frequency of day and night cough is not related to the degree of lung function damage.

4, diagnostic treatment: for patients with clinically suspected cough variant asthma, you can try bronchodilators, including inhaled or oral 2 receptor stimulants, theophylline, such as cough significantly reduced or disappeared, then support cough variant asthma diagnosis. If the effect is not significant, you can use inhaled corticosteroids or oral prednisone (30 ~ 40mg / day), most cough variant asthma can be significantly relieved within a week, a small number of patients need to be treated for two weeks to be effective.

Differential diagnosis

Because cough is a non-specific symptom of many diseases, it is necessary to ask for detailed history, comprehensive physical examination, chest X-ray, electrocardiogram, fiberoptic bronchoscopy and some special examinations to eliminate chronic diseases and intractable cough. Other diseases. Chronic bronchitis, gastroesophageal reflux, bronchial asthma, and posterior nostril drip are the most common causes of chronic cough, and some patients with gastroesophageal reflux can coexist with bronchial asthma. In addition, chronic heart failure, esophageal hiatal hernia, allergic rhinitis, hypertension, airway inflammation, tumors, tuberculosis, foreign body and smoke irritation, anxiety, etc. can lead to chronic cough.

The material in this site is intended to be of general informational use and is not intended to constitute medical advice, probable diagnosis, or recommended treatments.